Over the past decade many highly active and selective catalysts for hydrocarbon reactions have been derived from transition-metal complexes. These homogeneous complex catalysts have several advantages over conventional heterogeneous catalysts in that the active centers are readily accessible and reactions involving their use characterized by a high degree of selectivity and reproducibility. However, the use of homogeneous catalysts on an industrial scale can lead to numerous practical problems, including corrosion, deposition of the catalyst on the reactor walls and recovery of the catalyst from reaction products. One way of overcoming these problems while retaining the advantages of the transition-metal complex catalyst is to attach the complex to the surface of a solid support. In particular, increased attention has been given recently to anchoring homogeneous transition metal catalysts to polymeric supports through the formation of one or more chemical bonds between the surface of the support and a ligand group involved in the metal complex. The transition-metal complexes may be attached to the surfaces of both organic and inorganic solids. Generally, these hybrid or "heterogenized" catalysts have certain intrinsic advantages over their homogeneous counterparts, particularly: (1) ease of separation from products, (2) enhanced size and positional selectivity, (3) ability to carry out sequential catalytic reactions and (4) ease of catalyst recycle. A number of research groups have, in recent years, demonstrated that a variety of transition-metal organometallic species possess excellent activity and selectivity for hydrogenation, isomerization and hydroformylation when bonded to macroreticular polymeric resins. However, olefinic hydroformylation stuties have, to our knowledge, been carried out only with polymer anchored cobalt* and rhodium** catalyst complexes. The normal/iso aldehyde ratio with these catalysts is typically 1/3-3/1, hydroformylation being accompanied by concurrent isomerization of the unreacted olefin and reduction to alkanes. FNT *G. O. Evans et al, J. Organometal. Chem. 67, 295 (1974). FNT **See for example: K. G. Allum et al, J. Organometal. Chem., 87, 189 (1975): M. Capka et al, Tetrahedron Lett., 4787 (1971); and C. V. Pittman et al, J. Amer. Chem. Soc. 97, 1942 (1975).
In the broadest contemplated practice of this invention, aldehydes are produced from .alpha.-olefins substrates by the catalytically directed addition of hydrogen and carbon monoxide to said .alpha.-olefins in the presence of a catalytic quantity of a supported hydroformylation catalyst consisting of one or more platinum halides, in combination with one or more Group IVA metal halides (such as tin and germanium halides) bonded to nitrogen containing organic and or inorganic supports to form a reaction mixture, and heating the pressurized reaction mixture until substantial amounts of the desired aldehydes are produced.
In a narrower practice of this invention, aldehydic products containing from 3 to 31 carbon atoms are prepared by the catalytic addition of carbon monoxide and hydrogen to an .alpha.-olefin substrate containing from 2 to 30 carbon atoms by a process of:
(a) Admixing each mole of said .alpha.-olefin to be hydroformylated, in a deoxygenated reaction medium with at least a catalytic quantity of a supported hydroformylation catalyst consisting of one or more platinum halides, bonded to or anchored to one or more nitrogen containing organic and inorganic supports, to form a reaction mixture.
(b) Pressurizing said reaction mixture with at least sufficient carbon monoxide and hydrogen to satisfy the stoichiometry of the hydroformylation reaction described supra (Eq. 1);
(c) Heating said pressurized reaction mixture to temperatures of from about 20.degree. to 130.degree. C. until substantial formation of the predominantly linear alkyl aldehyde product is formed, and
(d) Isolating said aldehyde products contained therein.
In a yet narrower embodiment of this invention, aldehydic products containing 3 to 31 carbon atoms are prepared by the catalytic addition of hydrogen and carbon monoxide to an alpha-olefin substrate containing 2 to 30 carbon atoms by the following steps:
(a) Mixing the catalyst, comprising an insoluble, macroreticular nitrogen-containing organic polymer or silica supported, amine-stabilized platinum-tin halide complex, containing a tin to platinum atomic ratio of 0.5 to 30:1, in a deoxygenated inert solvent and pretreating with carbon monoxide at 250 to 4000 psig for 15 to 90 minutes at temperatures of 20.degree. to 90.degree. centigrade, to form a pretreated reaction mixture.
(b) Dispersing the alpha-olefin, in the ratio of one mole per 0.001 to 0.1 mole of platinum catalyst used, then pressurizing to at least 250 psig with carbon monoxide and additional sufficient hydrogen to satisfy the stoichiometry of the hydroformylation reaction referred to above (Eq. 1), to form a pretreated reaction mixture.
(c) Heating said pressurized reaction mixture to temperatures of 20.degree. to 130.degree. centigrade until substantial formation of the aldehydic product is achieved, and
(d) Isolating said aldehydic products contained therein.
In order to further aid in the understanding of this invention, the following additional disclosure is submitted: